No problem here (Score 2, Informative)

At my office, I have MCK units in the company's two buildings talking ADPCM32 over bridged D-Link 2000APs (yes, I'm a cheap bastard, but I was saving company money!) through a FreeSWAN/PIX VPN. Nine lines total, plus the usual data traffic. Works beautifully (as long as the APs don't freeze).